According to the Western-sponsored Budapest Memorandum, Kiev gave up its nuclear weapons in return for the Russian pledge of respect for Ukrainian territorial integrity. Russia’s full-fledged invasion of Ukraine has brought to mind a crucial post-Cold War agreement over Ukraine’s nuclear weapons capability – which resulted in Kiev giving up its nuclear arsenal in light of the US and UK's assurances that Moscow would respect the former Soviet republic’s sovereignty. Ukraine possessed the world’s third-largest nuclear arsenal, which consisted of at least 1,900 strategic nuclear warheads. The country had inherited that infrastructure from the former communist Soviet republic. If Ukraine...